Objective lens driver device and method of manufacturing the lens drive device

ABSTRACT

To provide an inexpensive and easily manufaturable objective lens driving apparatus. It has a configuration wherein a reinforcing rib part for reinforcing a coil restraining part of a support printed board is formed on a lens holder and ends of windings of a focusing coil and a tracking coil are wound around the support printed board and the reinforcing rib part in bundle for restraining.

TECHNICAL FIELD

[0001] This invention relates to an objective lens driving apparatus fordriving an objective lens in response to an applied control signal andperforming focusing and tracking with respect to an optical datarecording medium and its manufacturing method.

BACKGROUND ART

[0002] These days, optical disk apparatus (e.g. DVD disk apparatus) thatmounts an optical pickup (including an objective lens) for recording asignal onto or reproducing a signal from an optical data record medium(e.g. optical disk such as DVD disk) is now in increasing demand.

[0003] These optical disk apparatus have an objective lens drivingapparatus for driving an objective lens in response to a control signaland performing focusing control and tracking control.

[0004] This invention relates to an objective lens driving apparatus,and particularly to the configuration of a support printed board and itsperiphery for restraining the ends of windings of a focusing coil or atracking coil of the objective lens driving apparatus.

[0005] An Official Gazette of Japanese Laid-open Public PatentApplication Hei 5-342607 describes a conventional objective lens drivingapparatus having a support printed board for restraining the ends ofwindings of a focusing coil or a tracking coil.

[0006] The configuration will be explained hereinafter.

[0007]FIG. 14 shows a front view, a bottom view and a left side view ofthe conventional objective lens driving apparatus described in theOfficial Gazette of Japanese Laid-open Public Patent Application Hei5-342607.

[0008] In FIG. 14, 1 is an objective lens and 2 is a lens holder towhich the objective lens 1 are attached.

[0009] A focusing coil 3 for driving the objective lens 1 in thefocusing direction (a direction of an arrow shown in FIG. 14, that is,the same direction as that of optical axis of the objective lens 1) anda tracking coil 4 for driving the objective lens 1 in the trackingdirection (a direction of an arrow shown in FIG. 14) are wound aroundthe lens holder 2.

[0010] Two support printed boards 5 are fixed at two positions indicatedby a tip of arrow of the lens holder 2.

[0011] The starting ends and the terminating ends of windings of thefocusing coil 3 and the tracking coil 4 are restrained by winding a fewturns along coil restraining parts, which are located in the vicinity ofthe front end parts of the support printed boards 5 protruded from thetop surface and the bottom surface of the lens holder 2.

[0012]6 is a fixed member which is comprised of a printed board andreferred to as an act printed board. As shown in the left side view, theact printed board 6 has four patterns, each pattern having a land partand a through hole formed in the center or its periphery of the landpart at one end.

[0013]7 is a support block which has a recessed part injected withdamper material 8 therein and four through holes are formed in saidrecessed part. The act printed board 6 and the support block 7 are fixedso that four through holes of the act printed board 6 and four throughholes of the support block 7, respectively, are placed coaxially.

[0014] Each end of four suspension wires 9 made of conductive metal wireis fixed to the act printed board 6 by soldering through the throughhole of the act printed board 6 and the through hole of the supportblock 7 at one end, and is fixed to the coil restraining part of thesupport printed board 5 by soldering at the other end.

[0015] With the above-mentioned configuration, it is possible to obtaina conductive path which starts from one of the patterns of the actprinted board 6, through 2 suspension wires 9 connected thereto, a landpart of the support printed board 5 connected to the suspension wire 9,the focusing coil 3 connected to the land part of the support printedboard 5, other land part of the support printed board 5 connected toother end of the focusing coil 3, other suspension wire 9 connected tothe other land part of the support printed board 5, and returns to otherone of the patterns of the act printed board 6 connected to the othersuspension wire 9.

[0016] By feeding current of a focusing control signal to this path,focusing control of the objective lens 1 can be achieved.

[0017] Similarly as the focusing control signal, by feeding current of atracking control signal to the conductive path containing the other twopatterns of the act printed board 6, the other two suspension wires 9,the other two land parts of the support printed board 5, and thetracking coil 4, tracking control of the objective lens 1 can beachieved.

[0018] Furthermore, the support block 7 is fixed to a yoke 10 at theposition as shown in the figure.

[0019] The lens holder 2 is supported by four suspension wires 9 so asto be located at the center between permanent magnets 11 and 12.

[0020] A magnetic circuit consisting of the permanent magnets 11 and 12,and the yoke 10 provided as an adjunct with the permanent magnets 11 and12 generates a substantially uniform magnetic field in the vicinity ofthe focusing coil 3 and the tracking coil 4.

[0021] By feeding a focusing control signal to the focusing coil 3within the uniform magnetic field, Lorentz force is generated, therebyproducing a torque for driving the lens holder 2 in the focusingdirection.

[0022] Likewise, by feeding a tracking control signal to the trackingcoil 4 within the uniform magnetic field, Lorentz force is generated,thereby producing a torque for driving the lens holder 2 in the trackingdirection.

[0023] As four suspension wires 9 are made of flexible metal wire, thelens holder 2 undergoes displacement due to the above-mentioned torqueactuation.

[0024] Moreover, in the case that windings of the focusing coil 3 andthe tracking coil 4 are wound by an automatic winder, parts of thesupport printed board 5 are configured to protrude from the lens holder2 and the parts neighboring to the front ends of the protruded supportprinted board act as coil restraining parts, thereby facilitatingrestraint of the starting ends and the terminating ends of windings.

[0025] The objective lens driving apparatus is required to improvetracking sensitivity for corresponding to high-speed playback. As asolution, it is effective to reduce weight of the movable body.

[0026] Specific measures are thinning of the lens holder and weightreduction in the support printed board.

[0027] However, weight reduction causes rigidity degradation of themovable body, resulting in the deterioration of high-order resonancecharacteristic of the objective lens driving apparatus. Althoughthinning of the lens holder and weight reduction in the support printedboard are effective in improving tracking sensitivity, these membersbecome less integrated.

[0028] As a result, the coil restraining part of the support printedboard which protrudes from the lens holder has a separate vibration modeat high frequencies.

[0029] For that reason, with respect to the vibration characteristic ofthe objective lens driving apparatus, undesired resonance anddisturbance in phase occur and tracking performance of the objectivelens driving apparatus for the optical data recording mediumdeteriorates. Further, there is the possibility of consuming electricityunnecessary for tracking.

[0030] On the other hand, in order to facilitate the arrangement of thestarting ends and the terminating ends of the windings of the coilswound by an automatic winder, it is desirable to configure the coilrestraining part of the support printed board to protrude from the lensholder as mentioned above.

[0031] An object of the present invention is to provide an inexpensiveand easily manufacturable objective lens driving apparatus which isexcellent in tracking sensitivity and free from the undesired resonancemode and so on.

[0032] Another object of the present invention is to provide aninexpensive manufacturing method for manufacturing an objective lensdriving apparatus which is excellent in tracking sensitivity and freefrom the undesired resonance mode and so on without adding new process.

DISCLOSURE OF INVENTION

[0033] A first invention is an objective lens driving apparatuscharacterized by comprising an objective lens, a lens holder for holdingsaid objective lens, a focusing coil with a central axis substantiallyparallel to the focusing direction of said objective lens, a trackingcoil with a central axis substantially parallel to the trackingdirection of said objective lens, a magnet for generating a magneticfield in the vicinity of said focusing coil and tracking coil, a supportprinted board having coil restraining parts which protrudes from sidesurfaces of said lens holder and restrain ends of winding of at leasteither said focusing coil or tracking coil, and a plurality ofsuspension wires made of conductive material, wherein said lens holderhas a reinforcing rib which contacts with at least a part of the portionof said support printed board protruding from said lens holder.

[0034] The lens holder of the objective lens driving apparatus accordingto this invention has a reinforcing rib for supporting the coilrestraining part of the support printed board.

[0035] This can prevent the coil restraining part of the support printedboard from causing undesired resonance and unnecessary disturbance inphase.

[0036] This invention has the effect of realizing the inexpensiveobjective lens driving apparatus with high tracking sensitivity.

[0037] A second invention is the objective lens driving apparatusaccording to the first invention characterized by that the surface ofsaid reinforcing rib that does not contact with the side surface of saidlens holder forms an inclined plane with respect to the side surface ofthe lens holder, and winding of said coil restrained at said coilrestraining part is located along said inclined plane.

[0038] In the case that the whole back surface of the support printedboard is supported by the reinforcing rib, the winding of the coilaround the coil restraining part can interfere physically with (contactwith) the position of inserting the suspension wire.

[0039] In the objective lens driving apparatus according to thisinvention, the surface of said reinforcing rib that does not contactwith the side surface of said lens holder forms an inclined plane withrespect to the side surface of the lens holder (not parallel to the sidesurface of said lens holder).

[0040] Winding of coil is disposed along the inclined plane, therebypreventing the winding of coil from interfering with the insertionposition of the suspension wire.

[0041] According to this invention, the coil restraining part of thesupport printed board does not cause undesired resonance and unnecessarydisturbance in phase, and at the same time, it is possible to achievestable winding work of coil and stable insertion of the suspension wireduring assembly of the objective lens driving apparatus so that qualityof product in a factory can be improved.

[0042] This invention has the effect of realizing the inexpensive andeasily manufacturable objective lens driving apparatus with hightracking performance.

[0043] Further, this invention has the effect of realizing the objectivelens driving apparatus in which the starting end and the terminating endof the coil wound by an automated winder are easily restrained.

[0044] A third invention is an objective lens driving apparatus of thefirst invention characterized by that winding of said coil is restrainedat said restraining part by winding a turn or few turns around saidsupport printed board and said reinforcing rib.

[0045] According to this invention, said support printed board and saidreinforcing rib can become integrated without adhesive so that the coilrestraining part of the support printed board does not cause undesiredresonance and unnecessary disturbance in phase.

[0046] This invention has the effect of realizing the inexpensiveobjective lens driving apparatus with high tracking performance.

[0047] A fourth invention is an objective lens driving apparatus of thefirst invention or the third invention characterized by that saidreinforcing rib part has a stepped portion or a grooved portion andwinding of said coil which is restrained at said restraining part islocated along said stepped portion or said grooved portion.

[0048] This invention can prevent winding of the coil from interferingwith the insert position of the suspension wire.

[0049] Also, according to this invention, the coil restraining part ofthe support printed board does not cause undesired resonance andunnecessary disturbance in phase, and at the same time, it is possibleto achieve stable winding work of coil and stable insertion of thesuspension wire during assembly of the objective lens driving apparatusso that quality of product in a factory can be improved.

[0050] This invention has the effect of realizing the inexpensive andeasily manufacturable objective lens driving apparatus with hightracking performance.

[0051] Further, this invention has the effect of realizing the objectivelens driving apparatus in which the starting end and the terminating endof the coil wound by an automated winder are easily restrained.

[0052] A fifth invention is an objective lens driving apparatus of anyof the first invention to the third invention characterized by that saidsupport printed board has a plurality of notches and winding of saidcoil which is restrained at said restraining part is located along saidnotches.

[0053] This invention has the effect of realizing the objective lensdriving apparatus in which the starting end and the terminating end ofthe coil wound by an automated winder are easily restrained.

[0054] A sixth invention is-an objective lens driving apparatuscomprising an objective lens, a lens holder for holding said objectivelens, a focusing coil having a central axis substantially parallel to afocusing direction of said objective lens, a tracking coil having acentral axis substantially parallel to a tracking direction of saidobjective lens, a magnet for generating a magnetic field in the vicinityof said focusing coil and said tracking coil, a support printed boardwhich protrudes from side surfaces of said lens holder and has arestraining part for restraining end of winding of at least either saidfocusing coil or said tracking coil, a plurality of suspension wiresmade of conductive material, and an adhesive which is applied to acorner part defined by a protruded part of said support printed boardfrom said lens holder and a side surface of said lens holder.

[0055] According to this invention, the coil restraining part of thesupport printed board does not cause undesired resonance and unnecessarydisturbance in phase.

[0056] This invention has the effect of realizing the inexpensive andeasily manufacturable objective lens driving apparatus with hightracking performance.

[0057] A seventh invention is an objective lens driving apparatus of thesixth invention characterized by that said lens holder has a bonded partwith said support printed board, said bonded part comprising a firstdepression as an adhesive reservoir and a groove which extends from saidfirst depression to a base of said support printed board.

[0058] According to this invention, the coil restraining part of thesupport printed board does not cause undesired resonance and unnecessarydisturbance in phase.

[0059] Further, fixing firmly said support printed board by disposing soas to push said support printed board against said first depression, aswell as overflowing said adhesive to said corner part by extending saidadhesive along said groove of said lens holder which extends from saidfirst depression to said corner part can be achieved during a singleprocess. Therefore, the adhesive can be applied to said corner partwithout adding any new process. This invention has the effect ofrealizing the inexpensive and easily manufacturable objective lensdriving apparatus with high tracking performance.

[0060] A eighth invention is an objective lens driving apparatus of thesixth invention characterized by that said lens holder comprises asecond depression as an adhesive reservoir for bonding said objectivelens, and a groove which extends from said second depression to a baseof said support printed board.

[0061] According to this invention, the coil restraining part of thesupport printed board does not cause undesired resonance and unnecessarydisturbance in phase.

[0062] Further, by disposing a member so as to push a member againstsaid second depression, said member and said objective lens are fixedfirmly, and by extending said adhesive along said groove of said lensholder which extends from said first depression to said corner, saidadhesive can be overflowed to said corner part. Therefore, the adhesivecan be applied to said corner part without adding any new process.

[0063] This invention has the effect of realizing the inexpensive andeasily manufacturable objective lens driving apparatus with hightracking performance.

[0064] A ninth invention is a manufacturing method of the objective lensdriving apparatus of the sixth invention comprising steps of dropping anadhesive into said first depression formed on said lens holder, andfixing firmly said support printed board by pushing said support printedboard against said first depression, as well as overflowing saidadhesive to said corner part by extending said adhesive along saidgroove of said lens holder which extends from said first depression tosaid corner part.

[0065] According to this invention, the adhesive can be applied to saidcorner part without adding any new process. As a result, the coilrestraining part of the support printed board does not cause undesiredresonance and unnecessary disturbance in phase.

[0066] This invention has the effect of realizing the inexpensivemanufacturing method for manufacturing the objective lens drivingapparatus with high tracking performance.

[0067] A tenth invention is a manufacturing method of the objective lensdriving apparatus of the sixth invention comprising steps of dropping anadhesive into said second depression formed on said lens holder, andfixing firmly said objective lens by pushing a member against saidsecond depression, as well as overflowing said adhesive to said cornerpart by extending said adhesive along said groove of said lens holderwhich extends from said second depression to said corner part.

[0068] According to this invention, the adhesive can be applied to saidcorner part without adding any new process. As a result, the coilrestraining part of the support printed board does not cause undesiredresonance and unnecessary disturbance in phase.

[0069] This invention has the effect of realizing the inexpensivemanufacturing method for manufacturing the objective lens drivingapparatus with high tracking performance.

[0070] “Member” means an optional member. Typically, it is a lensprotector (FIG. 13).

[0071] The novel features of the invention will be hereinafter fullydescribed and particularly pointed out in the appended claims, and theconfiguration and details of the invention, together with other objectsand features thereof, will become better understood and appreciated byreference to the following detailed description when considered inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0072]FIG. 1 is a front view, a sectional view taken along the A-A lineand a sectional view taken along the B-B line of a movable section ofthe objective lens driving apparatus of embodiment 1.

[0073]FIG. 2 is a perspective view in schematic form depicting theconfiguration of the reinforcing rib of the objective lens drivingapparatus of embodiment 1.

[0074]FIG. 3 is a graph showing frequency characteristic of theobjective lens driving apparatus of embodiment 1.

[0075]FIG. 4 is a front view and a sectional view taken along the A-Aline of a movable section of the objective lens driving apparatus ofembodiment 2.

[0076]FIG. 5 is a perspective view in schematic form depicting theconfiguration of the reinforcing rib of the objective lens drivingapparatus of embodiment 2.

[0077]FIG. 6 is a front view and a sectional view taken along the A-Aline of a movable section of the objective lens driving apparatus ofembodiment 3.

[0078]FIG. 7 is a perspective view in schematic form depicting theconfiguration of the reinforcing rib of the objective lens drivingapparatus of embodiment 3.

[0079]FIG. 8 is a front view and a sectional view taken along the A-Aline of a movable section of the objective lens driving apparatus ofembodiment 4.

[0080]FIG. 9 is a perspective view in schematic form depicting theconfiguration of the reinforcing rib of the objective lens drivingapparatus of embodiment 4.

[0081]FIG. 10 is a front view, a bottom view and a sectional view takenalong the B-B line of a movable section of the objective lens drivingapparatus of embodiment 5.

[0082]FIG. 11 is a perspective view in schematic form depicting theconfiguration of the reinforcing rib of the objective lens drivingapparatus of embodiment 5, and a view showing a manufacturing method formanufacturing the objective lens driving apparatus of embodiment 5.

[0083]FIG. 12 is a front view of a movable section of the objective lensdriving apparatus of embodiment 6.

[0084]FIG. 13 is a perspective view in schematic form depicting theconfiguration of the reinforcing rib of the objective lens drivingapparatus of embodiment 6, and a view showing a manufacturing method formanufacturing the objective lens driving apparatus of embodiment 6.

[0085]FIG. 14 is a view depicting the configuration of the conventionalobjective lens driving apparatus.

[0086] It is noted that a part or whole of the figures are schematicallydepicted for diagrammatic representation and they do not necessarilyreflect actual relative size and position of components showed therein.

BEST MODE FOR EMBODYING THE INVENTION

[0087] Embodiments which makes a concrete explanation of best mode forembodying the present invention will be described herein after with theappended figures. However, the present invention is not limited to thefollowing embodiments unless it exceeds the extent of the spirit.

[0088] <<Embodiment 1>>

[0089] Referring to FIG. 1 to FIG. 3, an objective lens drivingapparatus of embodiment 1 according to the present invention will beexplained.

[0090] First, the vibration characteristic of the objective lens drivingapparatus will be explained.

[0091]FIG. 3 shows the frequency characteristic of displacement gain inthe tracking direction with respect to the objective lens drivingapparatus. The peak frequency having the highest displacement gain inthe whole frequency range is referred to as primary resonance and thepeak frequency in higher frequency range is referred to as high orderresonance.

[0092] And, undesired resonance appearing in proximity to 10 kHz in thedrawing is caused by self-resonance of a support printed board.

[0093] On the basis of gain crossover frequency fx shown in the drawing,low-frequency side indicates servo frequency range of the objective lensdriving apparatus (i.e. the frequency range in which vibration, errorand so on can be suppressed by controlling the objective lens drivingapparatus), and high-frequency side indicates non-servo frequency range(i.e. high-frequency range in which the objective lens driving apparatusgives no response).

[0094] In the presence of undesired resonance in the non-servo frequencyrange, when coil current exceeding minimum track displacement isapplied, tracking cannot be carried out with tracking accuracy in theobjective lens driving apparatus, potentially resulting in an off-trackstate.

[0095] However, as servo operation is not performed in this frequencyrange, the displacement is kept uncontrolled and off-track state cannotbe resolved.

[0096] In equipment using objective lens driving apparatus (e.g., DVDdevice), a phase compensating filter ensures phase margin of 35° to 60°known as stable for servo control in gain crossover frequency range. Atthat time, the presence of phase disturbance due to undesired resonancecan interfere with the provision of the phase margin. Therefore,undesired resonance in non-servo frequency range deteriorates trackingperformance of tracking control in the optical disk apparatus. Further,it causes unnecessary electricity consumption.

[0097] As described above, in order to achieve an optical disk apparatuswith high tracking performance, it is highly important to suppressself-resonance of a support printed board.

[0098] For this purpose, in the objective lens driving apparatus ofembodiment 1, a lens holder 13 has four reinforcing ribs 13 a so as tosuppress self-resonance of the support printed board.

[0099] The remaining structure of the apparatus is the same as thecorresponding structure of the above-mentioned conventional objectivelens driving apparatus.

[0100]FIG. 1 shows a front view, a sectional view taken along the A-Aline and a sectional view taken along the B-B line of a movable sectionof the objective lens driving apparatus of embodiment 1 according to thepresent invention. FIG. 2 shows a perspective view in schematic formdepicting the configuration of the reinforcing rib 13 a of the objectivelens driving apparatus of embodiment 1 (The reinforcing rib 13 a isrepresented larger than life.)

[0101] The movable section means movable parts held by a suspensionwires 9 in the objective lens driving apparatus, including an objectivelens 1, the lens holder 13, a focusing coil 3, a tracking coil 4,support printed boards 5, and the suspension wires 9.

[0102] As parts other than the movable parts are the same as thecorresponding parts of the above-mentioned conventional objective lensdriving apparatus, description is omitted.

[0103] In the objective lens driving apparatus of embodiment 1, partsexcept for the four reinforcing ribs 13 a of the lens holder andplacement of windings of coils (the focusing coil 3 and the trackingcoil 4) are the same as the corresponding parts of the conventionalobjective lens driving apparatus, these parts are identified by the samereference numbers. Description thereof is omitted.

[0104] As shown in FIG. 1 and FIG. 2, the reinforcing rib 13 a of thelens holder 13 closely contacts with the support printed board 5protruding from the side surfaces of the lens holder (front surface andback surface) (both ends of each of two support printed boards protrudefrom the side surfaces of the lens holder, respectively (at fourlocations in total)), thereby reinforcing the base of the supportprinted board 5. Preferably, the contact surfaces of the support printedboard 5 and the reinforcing rib 13 a are fixed to each other byadhesive.

[0105] A surface of the reinforcing rib that does not contact with theside surface of the lens holder forms an inclined plane with respect tothe side surface of the lens holder. The reinforcing rib 13 a ofembodiment 1 is shaped like a triangle pole with a right triangularcross section, and the contact surface with the printed board is shapedlike said right triangle.

[0106] Regarding a base side (the same plane surface as the side surfaceof the lens holder) as a bottom line of said triangle (one of the linesmaking a right angle), an apex of the triangle (the furthermost positionfrom the side surface of the lens holder) is located in the vicinity ofa coil restraining part of the support printed board (located near thefront end of the support printed board).

[0107] Cross section of the reinforcing rib may be shaped like atrapezoid in place of a triangle. A trapezoidal surface of thereinforcing rib that does not contact with the side surface of the lensholder forms an inclined plane with respect to the side surface of thelens holder.

[0108] At four coil restraining parts, the starting ends and theterminating ends of windings of the focusing coil 3 and the trackingcoil 4 are fixed, respectively.

[0109] Referring to a sectional view taken along the A-A line of FIG. 1(a sectional view viewed from right side along the A-A line of the frontview of FIG. 1) and FIG. 2, arrangement method of windings of coils willbe explained hereinafter.

[0110] Winding of the focusing coil 3 is wound a few turns along thecoil restraining part 5 a located in the vicinity of the front end ofthe support printed board for restraining (the starting end part of thefocusing coil 3 is formed), and after that, the winding drawn from saidstaring end part is located along the inclined plane of the reinforcingrib 13 a in the shape of a right triangle as a guideline.

[0111] The winding located along the inclined plane is led to a focusingcoil winding part of the lens holder 13 having reinforcing ribs. Afterthat, the winding is wound on it to form the focusing coil 3.

[0112] On the completion of winding up, the winding is located along theinclined plane of the reinforcing rib 13 a at the side of a coilrestraining part 5 b as a guideline.

[0113] The winding located along the inclined plane is led to the coilrestraining part 5 b located in the vicinity of the front end of thesupport printed board and is wound a few turns along the coilrestraining part 5 b for restraining (the terminating end part of thefocusing coil 3 is formed).

[0114] Similarly, the tracking coil 4 is also located along the inclinedplanes of other two reinforcing ribs as guidelines and wound on atracking coil winding part of the lens holder 13 having the reinforcingribs.

[0115] Referring to a cross sectional view taken along the B-B line ofFIG. 1, wiring paths 3 a and 3 b of the focusing coil 3 between the coilrestraining part 5 a of the support printed board 5 and the focusingcoil winding part of the lens holder 13 having the reinforcing ribs willbe described.

[0116] In the conventional objective lens driving apparatus, owing tothe absence of reinforcing rib (as there is no guideline for coil), whenthe winding is wound by an automated winder, the shortest path 3 a ofwiring is likely to be selected.

[0117] However, this raises a possibility that the shortest path 3 acontacts with the suspension wire 9 (the shortest path 3 a interfereswith the suspension wire 9) Assembly process of the objective lensdriving apparatus includes the inserting process of the suspension wire9 following the above-mentioned winding process. Therefore, when thesuspension wire contacts with the focusing coil, there is possibility ofa failure to insert the wire.

[0118] On the contrary, in the objective lens driving apparatus ofembodiment 1, the wiring path of the focusing coil 3 is guided by thereinforcing ribs so as to be fixed at the path 3 b.

[0119] On the wiring path 3 b, the winding does not contact with thesuspension wire 9. Accordingly, the above-mentioned problem does notoccur during assembly process, thereby facilitating assembly of theobjective lens driving apparatus and improving quality of product in afactory.

[0120] Next, the results of the present embodiment will be described. Byusing the lens holder with reinforcing ribs in the shape of righttriangle, undesired resonance of 6 dB (12 kHz) disappears and high orderresonance margin (difference between displacement gain of 1 kHz and peakof high order resonance) is improved from 40 dB to 45 dB.

[0121] This promotes the-tracking performance of the objective lensdriving apparatus for the optical data recording medium.

[0122] Further, it enables a stable arrangement of the starting ends andthe terminating ends of coils by automated winder (arrangement forrestraining the starting end and the terminating end of winding of thecoil at the support printed board), as well as insertion of thesuspension wire.

[0123] <<Embodiment 2>>

[0124] Referring to FIG. 4 and FIG. 5, an objective lens drivingapparatus of embodiment 2 according to the present invention will beexplained.

[0125] In order to suppress self-resonance of a support printed board,the objective lens driving apparatus of embodiment 2 comprises a lensholder 14 having four reinforcing ribs and a support printed board 15with a plurality of notches. The reinforcing rib 14 a is different fromthat of embodiment 1 in shape.

[0126] The remaining structure of the apparatus is the same as thecorresponding structure of the above-mentioned conventional objectivelens driving apparatus.

[0127]FIG. 4 shows a front view, a sectional view taken along the A-Aline of a movable section of the objective lens driving apparatus ofembodiment 2. FIG. 5 shows a perspective view in schematic formdepicting the configuration of the reinforcing rib 14 a of the objectivelens driving apparatus of embodiment 2 (The reinforcing rib isrepresented larger than life.).

[0128] The movable section means movable parts held by suspension wires9 in the objective lens driving apparatus, including the objective lens1, the lens holder 14, the focusing coil 3, the tracking coil 4, thesupport printed boards 15, and the suspension wires 9.

[0129] As parts other than the movable parts are the same as thecorresponding parts of the above-mentioned conventional objective lensdriving apparatus, description is omitted.

[0130] In the objective lens driving apparatus of embodiment 2, partsexcept for four reinforcing ribs 14 a of the lens holder, plural notchesof the support printed board 15 and placement of windings of coils (thefocusing coil 3 and the tracking coil 4) are the same as thecorresponding parts of the conventional objective lens drivingapparatus, these parts are identified by the same reference numbers.Description thereof is omitted.

[0131] As shown in FIG. 4 and FIG. 5, the reinforcing rib 14 a of thelens holder 14 with reinforcing ribs closely contacts with the supportprinted board 15 protruding from the side surfaces of the lens holder(front surface and back surface) (both ends of each of two supportprinted boards protrude from the side surfaces of the lens holder,respectively (at four locations in total)), thereby reinforcing the baseof the support printed board 15.

[0132] At four coil restraining parts, the starting ends and theterminating ends of windings of the focusing coil 3 and the trackingcoil 4 are fixed.

[0133] In embodiment 2, the contact surfaces of the support printedboard 15 and the reinforcing rib 14 a may be fixed to each other byadhesive or may not be fixed.

[0134] At the coil restraining part, winding of a coil is wound a fewturns around the reinforcing rib 14 a and the support printed board 15with notches so as to tie the reinforcing rib 14 a and the supportprinted board 15 with notches in bundle. In this way, the reinforcingrib 14 a and the support printed board 15 with notches are firmly fixedto each other by winding of the coil.

[0135] With this configuration, resonance of the support printed boardwith notches 15 can be suppressed by the reinforcing rib 14 a.

[0136] The reinforcing rib 14 a is formed so as to have the same heightas the support printed board 15 and the same width as or narrower widththan the notched portion of the support printed board 15. The supportprinted board 15 with notches comprises a plurality of notches 15 b and15 c (the notch may be single) in addition to the coil restraining parts15 a and 15 d.

[0137] Referring to a sectional view taken along the A-A line of FIG. 4(a sectional view viewed from right side along the A-A line of the frontview of FIG. 4) and FIG. 5, arrangement method of windings of coils willbe explained hereinafter.

[0138] At the coil restraining part 15 a in the vicinity of the frontend of the support printed board, winding of the focusing coil 3 iswound a few turns around the reinforcing rib 14 a and the supportprinted board 15 with notches so as to tie the reinforcing rib 14 a andthe support printed board 15 with notches in bundle for restraining (thestarting end part of the focusing coil 3 is formed), and after that, thewinding drawn from said staring end part is led to the focusing coilwinding part of the lens holder 14 having reinforcing ribs through thenotch 15 b of the support printed board with notches (being guided bythe notch 15 b). After that, the winding is wound on it to form thefocusing coil 3. On the completion of winding work, the winding is ledto the coil restraining part 15 d through the notch 15 c of the supportprinted board with notches (being guided by the notch 15 c).

[0139] At the coil restraining part 15 d, winding of the focusing coil 3is wound a few turns around the reinforcing rib and the support printedboard 15 with notches so as to tie the reinforcing rib and the supportprinted board 15 with notches in bundle for restraining (the terminatingend part of the focusing coil 3 is formed).

[0140] Similarly, winding of the tracking coil 4 is also wound a fewturns around the reinforcing rib and the support printed board 15 withnotches for restraining, and after that, the restrained winding is ledto the tracking coil winding part of the lens holder 14 with reinforcingribs using the notches 15 b and 15 c of the support printed board withnotches as guides. The winding is wound on said tracking coil windingpart.

[0141] In the objective lens driving apparatus of embodiment 2, a wiringpath of the focusing coil 3 is guided by the notches 15 b and 15 c ofthe support printed board with notches so as to be fixed at the path 3 b(a sectional view taken along B-B line of FIG. 1).

[0142] On the wiring path 3 b, the winding does not contact with thesuspension wire 9. Accordingly, no problem occurs during assemblyprocess, thereby facilitating assembly of the objective lens drivingapparatus and improving quality of product in a factory.

[0143] According to this embodiment, undesired resonance of 6 dB (12kHz) disappears and high order resonance margin (difference betweendisplacement gain of 1 kHz and peak of high order resonance) is improvedfrom 40 dB to 45 dB.

[0144] This promotes tracking performance of the objective lens drivingapparatus for the optical data recording medium.

[0145] Further, it enables a stable arrangement of the starting ends andthe terminating ends of windings of the coils by automated winder(arrangement for restraining the starting ends and the terminating endsof windings of the coils at the support printed board), as well asinsertion of the suspension wire.

[0146] <<Embodiment 3>>

[0147] Referring to FIG. 6 and FIG. 7, an objective lens drivingapparatus of embodiment 3 according to the present invention will beexplained.

[0148] In order to suppress self-resonance of a support printed board,the objective lens driving apparatus of embodiment 3 comprises a lensholder 16 having four reinforcing ribs. The reinforcing rib 16 a isdifferent from that of embodiment 1 or embodiment 2 in shape.

[0149] The remaining structure of the apparatus is the same as thecorresponding structure of the above-mentioned conventional objectivelens driving apparatus.

[0150]FIG. 6 shows a front view, a sectional view taken along the A-Aline of a movable section of the objective lens driving apparatus ofembodiment 3. FIG. 7 shows a perspective view in schematic formdepicting the configuration of the reinforcing rib 16 a of the objectivelens driving apparatus of embodiment 3. (The reinforcing rib isrepresented larger than life.)

[0151] The movable section means movable parts held by the suspensionwires 9 in the objective lens driving apparatus, including the objectivelens 1, the lens holder 16, the focusing coil 3, the tracking coil 4,the support printed boards 5, and the suspension wires 9.

[0152] As parts other than the movable parts are the same as thecorresponding parts of the above-mentioned conventional objective lensdriving apparatus, description is omitted.

[0153] In the objective lens driving apparatus of embodiment 3, partsexcept for the four reinforcing ribs 16 a of the lens holder andplacement of windings of coils (the focusing coil 3 and the trackingcoil 4) are the same as the corresponding parts of the conventionalobjective lens driving apparatus, these parts are identified by the samereference numbers. Description thereof is omitted.

[0154] As shown in FIG. 6 and FIG. 7, the reinforcing rib 16 a of thelens holder 16 closely contacts with the support printed board 5protruding from the side surfaces of the lens holder (front surface andback surface) (both ends of each of two support printed boards protrudefrom the side surfaces of the lens holder, respectively (at fourlocations in total)), thereby reinforcing the base of the supportprinted board.

[0155] At four coil restraining parts, each of the starting ends and theterminating ends of windings of the focusing coil 3 and the trackingcoil 4 are fixed, respectively.

[0156] In embodiment 3, the contact surfaces of the support printedboard and the reinforcing rib may be fixed to each other by adhesive ormay not be fixed.

[0157] At the coil restraining part, winding of a coil is wound a fewturns around the reinforcing rib 16 a and the support printed board 5 soas to tie the reinforcing rib 16 a and the support printed board 5 inbundle. In this way, the reinforcing rib 16 a and the support printedboard 5 are firmly fixed to each other by winding of the coil.

[0158] With this configuration, resonance of the support printed boardcan be suppressed by the reinforcing rib.

[0159] The reinforcing rib 16 a is formed so as to have the same heightas the support printed board 5 and the same width as or narrower widththan the notched portion of the support printed board.

[0160] Referring to a sectional view taken along the A-A line of FIG. 6(a sectional view viewed from right side along the A-A line of the frontview of FIG. 6) and FIG. 7, arrangement method of windings of coils willbe explained hereinafter.

[0161] At the coil restraining part 5 a in the vicinity of the front endof the support printed board, winding of the focusing coil 3 is wound afew turns around the reinforcing rib 16 a and the support printed board5 so as to tie the reinforcing rib 16 a and the support printed board 5in bundle for restraining (the starting end part of the focusing coil 3is formed), and after that, the winding drawn from said staring end partis located along an inclined plane (a plane which is not parallel to aside surface of the lens holder) of upper part of a stepped portionformed on the reinforcing rib 16 a (being guided by the inclined plane)and then is led to the focusing coil winding part of the lens holder 16.After that, the winding is wound on it to form the focusing coil 3.

[0162] On the completion of the winding work, the winding is locatedalong an inclined plane of upper part of a stepped portion formed on thereinforcing rib 16 a (being guided by the inclined plane) and then isled to the coil restraining part 15 b in the vicinity of the front endof the support printed board.

[0163] At the coil restraining part 5 b, winding of the focusing coil 3is wound a few turns around the reinforcing rib 16 a and the supportprinted board 5 so as to tie the reinforcing rib 16 a and the supportprinted board 5 in bundle for restraining (the terminating end part ofthe focusing coil 3 is formed).

[0164] Similarly, winding of the tracking coil 4 is also wound a fewturns around the reinforcing rib 16 a and the support printed board 5for restraining by using a grooved portion of the reinforcing rib 16 aas a guide, and then is led to the tracking coil winding part of thelens holder for winding.

[0165] In the objective lens driving apparatus of embodiment 3, a wiringpath of the focusing coil 3 is guided by the inclined plane of the upperpart of the stepped portion formed on the reinforcing rib so as to befixed at the path 3 b (a sectional view taken along the B-B line of FIG.1).

[0166] On the wiring path 3 b, the winding does not contact with thesuspension wire 9. Accordingly, no problem occurs during assemblyprocess, thereby facilitating assembly of the objective lens drivingapparatus and improving quality of product in a factory.

[0167] According to this embodiment, undesired resonance of 6 dB (12kHz) disappears and high order resonance margin (difference betweendisplacement gain of 1 kHz and peak of high order resonance) is improvedfrom 40 dB to 45 dB.

[0168] This promotes tracking performance of the objective lens drivingapparatus for the optical data recording medium.

[0169] Further, it enables a stable arrangement of the starting ends andthe terminating ends of windings of the coils by automated winder(arrangement for restraining the starting ends and the terminating endsof windings of the coils at the support printed board), as well asinsertion of the suspension wire.

[0170] <<Embodiment 4>>

[0171] Referring to FIG. 8 and FIG. 9, an objective lens drivingapparatus of embodiment 4 according to the present invention will beexplained.

[0172] In order to suppress self-resonance of a support printed board,the objective lens driving apparatus of embodiment 4 comprises a lensholder 17 having four reinforcing ribs. The reinforcing rib 17 a isdifferent from that of embodiment 1, embodiment 2 or embodiment 3 inshape.

[0173] The remaining structure of the apparatus is the same as thecorresponding structure of the above-mentioned conventional objectivelens driving apparatus.

[0174]FIG. 8 shows a front view, a sectional view taken along the A-Aline of a movable section of the objective lens driving apparatus ofembodiment 4. FIG. 9 shows a perspective view in schematic formdepicting the configuration of the reinforcing rib 17 a of the objectivelens driving apparatus of embodiment 4 (The reinforcing rib isrepresented larger than life.).

[0175] The movable section means movable parts held by the suspensionwires 9 in the objective lens driving apparatus, including the objectivelens 1, the lens holder 17, the focusing coil 3, the tracking coil 4,the support printed boards 5, and the suspension wires 9.

[0176] As parts other than the movable parts are the same as thecorresponding parts of the above-mentioned conventional objective lensdriving apparatus, description is omitted.

[0177] In the objective lens driving apparatus of embodiment 4, partsexcept for the four reinforcing ribs 17 a of the lens holder andplacement of windings of coils (the focusing coil 3 and the trackingcoil 4) are the same as the corresponding parts of the conventionalobjective lens driving apparatus, these parts are identified by the samereference numbers. Description thereof is omitted.

[0178] As shown in FIG. 8 and FIG. 9, the reinforcing rib 17 a of thelens holder 17 closely contacts with the support printed board 5protruding from the side surfaces of the lens holder (front surface andback surface) (both ends of each of two support printed boards protrudefrom the side surfaces of the lens holder, respectively (at fourlocations in total)), thereby reinforcing the base of the supportprinted board.

[0179] At four coil restraining parts, the starting ends and theterminating ends of windings of the focusing coil 3 and the trackingcoil 4 are fixed.

[0180] In embodiment 4, the contact surfaces of the support printedboard and the reinforcing rib may be fixed to each other by adhesive ormay not be fixed.

[0181] At the coil restraining part, winding of a coil is wound a fewturns around the reinforcing rib 17 a and the support printed board 5 soas to tie the reinforcing rib and the support printed board 5 in bundle.In this way, the reinforcing rib 17 a and the support printed board 5are firmly fixed to each other by the winding of the coil.

[0182] With this configuration, resonance of the support printed board 5can be suppressed by the reinforcing rib.

[0183] The reinforcing rib 17 a is formed so as to have the same heightas the support printed board 5 and the same width as or narrower widththan the notched portion of the support printed board.

[0184] Referring to a sectional view taken along the A-A line of FIG. 8(a sectional view viewed from right side along the A-A line of the frontview of FIG. 8) and FIG. 9, arrangement method of windings of coils willbe explained hereinafter.

[0185] At the coil restraining part 5 a in the vicinity of the front endof the support printed board, winding of the focusing coil 3 is wound afew turns around the reinforcing rib 17 a and the support printed board5 so as to tie the reinforcing rib 17 a and the support printed board 5in bundle for restraining (the starting end part of the focusing coil 3is formed), and then, the winding drawn from said staring end part isled to the focusing coil winding part of the lens holder 17 through agrooved portion formed on the reinforcing rib 17 a. After that, thewinding is wound on it to form the focusing coil 3.

[0186] On the completion of the winding work, the winding is led to thecoil restraining part 5 b in the vicinity of the front end of thesupport printed board through the grooved portion formed on thereinforcing rib 17 a (being guided by the grooved portion).

[0187] At the coil restraining part 5 b, winding of the focusing coil 3is wound a few turns around the reinforcing rib 17 a and the supportprinted board 5 so as to tie the reinforcing rib 17 a and the supportprinted board 5 in bundle for restraining (the terminating end part ofthe focusing coil 3 is formed).

[0188] Similarly, winding of the tracking coil 4 is also wound a fewturns around the reinforcing rib 17 a and the support printed board 5for restraining, being guided by the grooved portion of the reinforcingrib 17 a as a guide, and then is wound on the tracking coil winding partof the lens holder 17 with reinforcing ribs.

[0189] In the objective lens driving apparatus of embodiment 4, a wiringpath of the focusing coil 3 is guided by the groove of the reinforcingrib so as to be fixed at the path 3 b (a sectional view taken along theB-B line of FIG. 1).

[0190] On the wiring path 3 b, the winding does not contact with thesuspension wire 9. Accordingly, no problem occurs during assemblyprocess, thereby facilitating assembly of the objective lens drivingapparatus and improving quality of product in a factory.

[0191] According to this embodiment, undesired resonance of 6 dB (12kHz) disappears and high order resonance margin (difference betweendisplacement gain of 1 kHz and peak of high order resonance) is improvedfrom 40 dB to 45 dB.

[0192] This promotes tracking performance of the objective lens drivingapparatus for the optical data recording medium.

[0193] Further, it enables a stable arrangement of the starting ends andthe terminating ends of windings of the coils by automated winder(arrangement for restraining the starting ends and the terminating endsof windings of the coils at the support printed board), as well asinsertion of the suspension wire.

[0194] <<Embodiment 5>>

[0195] Referring to FIG. 10 and FIG. 11, an objective lens drivingapparatus of embodiment 5 according to the present invention will beexplained.

[0196] In the objective lens driving apparatus of embodiment 5, anadhesive is applied to the corner part formed by the part of the supportprinted board 5 which protrudes from said lens holder and the sidesurface of the lens holder 18 in order to suppress self-resonance of thesupport printed board. Further, the lens holder 18 has a pasted partwith said support printed board 5.

[0197] The above-mentioned pasted part has a first depression as anadhesive reservoir and a groove which extends from the above-mentionedfirst depression to a base of the above-mentioned support printed board.

[0198] The remaining structure of the apparatus is the same as thecorresponding structure of the above-mentioned conventional objectivelens driving apparatus.

[0199]FIG. 10 shows a front view, a right side view (showing theappearance of the apparatus from which the support printed board 5 isremoved), and a sectional view taken along the B-B line of a movablesection of the objective lens driving apparatus of embodiment 5. FIG.11(a) shows a perspective view in schematic form depicting theconfiguration of the reinforcing rib of the objective lens drivingapparatus of embodiment 5 (The reinforcing rib is represented largerthan life.), and FIGS. 11(b) and (c) show the manufacturing method ofthe objective lens driving apparatus according to this invention.

[0200] The movable section means movable parts held by the suspensionwires 9 in the objective lens driving apparatus, including the objectivelens 1, the lens holder 18, the focusing coil 3, the tracking coil 4,the support printed boards 5, and the suspension wires 9.

[0201] As parts other than the movable parts are the same as thecorresponding parts of the above-mentioned conventional objective lensdriving apparatus, description is omitted.

[0202] As shown in the right side view of FIG. 10 and FIG. 11, the lensholder 18 comprises a first depression 18 a and a groove 18 b on thebottom (an applied area of adhesive for bonding of the support printedboard 5 with the lens holder 18). Both of the bonded parts (twolocations) of two support printed boards are same in configuration.

[0203] In FIG. 11(b), the adhesive 19 a is mounted on the firstdepression 18 a enough to bulge and immediately afterward, the supportprinted board 5 is pushed onto it in the direction shown by an arrow 20.

[0204] By pushing off the support printed board 5, the adhesive 19 aextends along the groove.

[0205] As a result, as shown in FIG. 11(c), the support printed board 5is stuck and fixed to the bottom surface of the lens holder.

[0206] Further, the adhesive extending along the groove overflows intothe corner part defined by the part of the support printed board 5 whichprotrudes from said lens holder and the side surfaces (front surface andback surface) of said lens holder 18 (the end part of the groove leadsup to the corner part).

[0207] The overflowed adhesive 19 b becomes hardened at the corner part,thereby reinforcing the base of the support printed board andsuppressing self-resonance of the support printed board 5.

[0208] According to this embodiment, undesired resonance of 6 dB (12kHz) disappears and high order resonance margin (difference betweendisplacement gain of 1 kHz and peak of high order resonance) is improvedfrom 40 dB to 45 dB.

[0209] This promotes tracking performance of the objective lens drivingapparatus for the optical data recording medium.

[0210] Further, the manufacturing method enables reinforcement of thebase of the support printed board without adding any new process.

[0211] <<Embodiment 6>>

[0212] Referring to FIG. 12 and FIG. 13, an objective lens drivingapparatus of embodiment 6 according to the present invention will beexplained.

[0213] In the objective lens driving apparatus of embodiment 6, anadhesive is applied to the corner part formed by the part of the supportprinted board 5 which protrudes from said lens holder and the sidesurface (front surface) of a lens holder 21 in order to suppressself-resonance of the support printed board.

[0214] A lens 1 is fitted to the lens holder 21. On the front surface, asecond depression 21 a and a groove 21 b which extends from the seconddepression 21 a to the lens land said corner part, respectively, areformed. (FIG. 12).

[0215] The remaining structure of the apparatus is the same as thecorresponding structure of the above-mentioned conventional objectivelens driving apparatus.

[0216]FIG. 12 shows a front view of a movable section of the objectivelens driving apparatus of embodiment 6. FIG. 13(a) shows a perspectiveview in schematic form depicting the configuration of the reinforcingrib of the objective lens driving apparatus of embodiment 6 (Thereinforcing rib is represented larger than life.), and FIGS. 13(b) and(c) show the manufacturing method of the objective lens drivingapparatus according to the present invention.

[0217] The movable section means movable parts held by the suspensionwires 9 in the objective lens driving apparatus, including the objectivelens 1, the lens holder 21, the focusing coil 3, the tracking coil 4,the support printed boards 5, the suspension wires 9, and a lensprotector 23 (The lens protector 23 is shown in FIG. 13).

[0218] As parts other than the movable parts are the same as thecorresponding parts of the above-mentioned conventional objective lensdriving apparatus, description is omitted.

[0219] In FIG. 13(b), adhesive 22 a is mounted on the second depression21 a enough to bulge and immediately afterward, the lens protector 23 ispushed onto it in the direction shown by an arrow 24.

[0220] By pushing off the lens protector 23, the adhesive 22 a extendsalong the groove.

[0221] As a result, as shown in FIG. 13(c), the lens protector 23 isstuck and fixed to the front surface of the lens holder.

[0222] The adhesive which extends along the groove 21 b reaches thecircumference of the objective lens 1 so as to fix the objective lens tothe lens holder.

[0223] Further, the adhesive which extends along the groove 21 boverflows into the corner part formed by the part of the support printedboard 5 which protrudes from said lens holder and the side surfaces ofsaid lens holder 21 (The end part of the groove leads up to the cornerpart).

[0224] The overflowed adhesive 22 b becomes hardened at the corner part,thereby reinforcing the base of the support printed board andsuppressing self-resonance of the support printed board 5.

[0225] Moreover, in embodiment 6, only the base of the support printedboard protruding from the front surface of the lens holder isreinforced. Therefore, with respect to the reinforcement of the base ofthe support printed board protruding from the back surface of the lensholder, it is desirable to adopt the method in embodiment 5 and so on.

[0226] According to this embodiment, undesired resonance of 6 dB (12kHz) disappears and high order resonance margin (difference betweendisplacement gain of 1 kHz and peak of high order resonance) is improvedfrom 40 dB to 45 dB.

[0227] This promotes tracking performance of the objective lens drivingapparatus for the optical data recording medium.

[0228] The lens protector 23 is made of soft molding material such asDURACON (registered trademark) and tubular part thereof protrudesfurther forward than the front surface of the lens.

[0229] In the case where an optical pickup operates irregularly, thesoft lens protector 23 hits against the recording medium, but theobjective lens 1 which is located at the position recessed from thefront surface of the lens protector does not hit against the recordingmedium.

[0230] The lens protector 23 protects the recording medium and theobjective lens 1 from possible breakage in the above-mentioned way.Therefore, the lens protector 23 is useful in itself and it is not a newadded component for the purpose of reinforcing the support printed board5 in the present invention.

[0231] The object lens driving apparatus of embodiment 6 has the effectof achieving the object lens driving apparatus with high trackingperformance without adding any new component.

[0232] Further, by the above-mentioned manufacturing method, the base ofthe support printed board 5 protruding forward can be reinforced withoutadding any new process.

[0233] According to this invention, the coil restraining part of thesupport printed board does not cause undesired resonance and unnecessarydisturbance in phase, and it is therefore possible to obtain theadvantageous effect of achieving the inexpensive and easilymanufacturable objective lens driving apparatus with high trackingperformance.

[0234] Furthermore, according to this invention, it is possible toobtain the advantageous effect of achieving the objective lens drivingapparatus in which the starting end and the terminating end of windingof the coil wounded by an automated winder are easy to be restrained.

[0235] According to this invention, it is possible to obtain theadvantageous effect of achieving the inexpensive manufacturing method ofthe objective lens driving apparatus with high tracking performancewithout adding any new manufacturing process.

[0236] While preferred embodiments have been described of the inventionwith a certain degree of particularity, it is understood that thepresent disclosure of the preferred embodiments have been changed in thedetails of construction and the varied combination and arrangement ofparts may be achieved without departing from the scope and the spirit ofthe claimed invention.

[0237] Industrial Applicability

[0238] The objective lens driving apparatus and manufacturing methodthereof of the present invention are applicable as the objective lensdriving apparatus and its manufacturing method for performing focusingand tracking with respect to optical data recording medium (for example,DVD disc).

1. An objective lens driving apparatus characterized by comprising: an objective lens; a lens holder for holding said objective lens; a focusing coil having a central axis substantially parallel to a focusing direction of said objective lens; a tracking coil having a central axis substantially parallel to a tracking direction of said objective lens; a magnet for generating a magnetic field in the vicinity of said focusing coil and said tracking coil; a support printed board which protrudes from side surface of said lens holder and has a restraining part for restraining end of winding of at least either said focusing coil or said tracking coil; and a plurality of suspension wires made of conductive material, wherein said lens holder has a reinforcing rib which contacts at least partially with a protruded part of said support printed board from said lens holder.
 2. An objective lens driving apparatus described in claim 1, characterized by that a surface of said reinforcing rib which is not in contact with a side surface of said lens holder forms an inclined plane with respect to said side surface of said lens holder and winding of said coil which is restrained at said coil restraining part is located along said inclined plane.
 3. An objective lens driving apparatus described in claim 1, characterized by that winding of said coil is restrained at said restraining part by winding a turn or few turns around said support printed board and said reinforcing rib.
 4. An objective lens driving apparatus described in claim 1 or claim 3, characterized by that said reinforcing rib part has a stepped portion or a grooved portion and winding of said coil which is restrained at said restraining part is located along said stepped portion or said grooved portion.
 5. An objective lens driving apparatus described in any of claim 1 to claim 3, characterized by that said support printed board has a plurality of notches and winding of said coil which is restrained at said restraining part is located along said notches.
 6. An objective lens driving apparatus comprising: an objective lens; a lens holder for holding said objective lens; a focusing coil having a central axis substantially parallel to a focusing direction of said objective lens; a tracking coil having a central axis substantially parallel to a tracking direction of said objective lens; a magnet for generating a magnetic field in the vicinity of said focusing coil and said tracking coil; a support printed board which protrudes from side surfaces of said lens holder and has a restraining part for restraining end of winding of at least either said focusing coil or said tracking coil; a plurality of suspension wires made of conductive material; and adhesive for reinforcement which is applied to a corner part defined by a protruded part of said support printed board from said lens holder and a side surface of said lens holder.
 7. An objective lens driving apparatus described in claim 6, characterized by that said lens holder has a pasted part with said support printed board, said pasted part comprising a first depression as an adhesive reservoir and a groove which extends from said first depression to a base of said support printed board.
 8. An objective lens driving apparatus described in claim 6, characterized by that said lens holder comprises a second depression as an adhesive reservoir, a groove which extends from said second depression to said objective lens and a groove which extends from said second depression to a base of said support printed board.
 9. A manufacturing method of the objective lens driving apparatus described in claim 6 comprising steps of: dropping adhesive into said first depression formed on said lens holder; fixing firmly said support printed board by pushing said support printed board against said first depression, as well as overflowing said adhesive to said corner part by extending said adhesive along said groove of said lens holder which extends from said first depression to said corner part.
 10. A manufacturing method of the objective lens driving apparatus described in claim 6 comprising steps of: dropping adhesive into said second depression formed on said lens holder; fixing firmly said objective lens by pushing a member against said second depression, as well as overflowing said adhesive to said corner part by extending said adhesive along said groove of said lens holder which extends from said second depression to said corner part. 